This invention relates to surveillance systems and, in particular, to a surveillance camera which is environmentally sealed.
Video surveillance cameras installed in outdoor locations need an enclosure that can withstand a wide range of ambient temperatures and weather conditions without adversely affecting operation of the video camera. Normally, the camera enclosure has a weatherability rating under the Ingress Protection (IP) rating system where the first digit indicates the protection against solid objects and the second digit indicates the protection against liquids. For example, a camera enclosure having a rating of IP66 would not allow any ingress of dust and would not allow harmful quantities of water from heavy seas or water projected in powerful jets from entering the enclosure. A lower IP rating allows greater invasion of dust, contaminants and water, which limits the applications of the surveillance camera and its desirability.
In addition, pressurized enclosures with several screw type fasteners spaced around a flange or trim ring have been used. However, this type of enclosure has allowed the nitrogen or other gases used to create a positive pressure within the enclosure to escape thereby resulting in less than satisfactory performance of the camera and requiring repair service to correct the problem. Accordingly, it is desirable to have a video surveillance camera enclosure that maintains an environmental seal.